EP0160995A2 - Arrangement de circuit pour la production d'impulsions érosives dans une installation d'étincelage érosif - Google Patents

Arrangement de circuit pour la production d'impulsions érosives dans une installation d'étincelage érosif Download PDF

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Publication number
EP0160995A2
EP0160995A2 EP85105692A EP85105692A EP0160995A2 EP 0160995 A2 EP0160995 A2 EP 0160995A2 EP 85105692 A EP85105692 A EP 85105692A EP 85105692 A EP85105692 A EP 85105692A EP 0160995 A2 EP0160995 A2 EP 0160995A2
Authority
EP
European Patent Office
Prior art keywords
signal
circuit
circuit arrangement
control
signals
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
EP85105692A
Other languages
German (de)
English (en)
Other versions
EP0160995A3 (en
EP0160995B1 (fr
Inventor
Silvano Dresti
Ernst Bühler
René Derighetti
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Agie Charmilles SA
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Agie Charmilles SA
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Publication date
Application filed by Agie Charmilles SA filed Critical Agie Charmilles SA
Publication of EP0160995A2 publication Critical patent/EP0160995A2/fr
Publication of EP0160995A3 publication Critical patent/EP0160995A3/de
Application granted granted Critical
Publication of EP0160995B1 publication Critical patent/EP0160995B1/fr
Expired legal-status Critical Current

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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23H—WORKING OF METAL BY THE ACTION OF A HIGH CONCENTRATION OF ELECTRIC CURRENT ON A WORKPIECE USING AN ELECTRODE WHICH TAKES THE PLACE OF A TOOL; SUCH WORKING COMBINED WITH OTHER FORMS OF WORKING OF METAL
    • B23H7/00—Processes or apparatus applicable to both electrical discharge machining and electrochemical machining
    • B23H7/14—Electric circuits specially adapted therefor, e.g. power supply
    • B23H7/20—Electric circuits specially adapted therefor, e.g. power supply for program control, e.g. adaptive
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23H—WORKING OF METAL BY THE ACTION OF A HIGH CONCENTRATION OF ELECTRIC CURRENT ON A WORKPIECE USING AN ELECTRODE WHICH TAKES THE PLACE OF A TOOL; SUCH WORKING COMBINED WITH OTHER FORMS OF WORKING OF METAL
    • B23H1/00—Electrical discharge machining, i.e. removing metal with a series of rapidly recurring electrical discharges between an electrode and a workpiece in the presence of a fluid dielectric
    • B23H1/02—Electric circuits specially adapted therefor, e.g. power supply, control, preventing short circuits or other abnormal discharges
    • B23H1/022—Electric circuits specially adapted therefor, e.g. power supply, control, preventing short circuits or other abnormal discharges for shaping the discharge pulse train
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23H—WORKING OF METAL BY THE ACTION OF A HIGH CONCENTRATION OF ELECTRIC CURRENT ON A WORKPIECE USING AN ELECTRODE WHICH TAKES THE PLACE OF A TOOL; SUCH WORKING COMBINED WITH OTHER FORMS OF WORKING OF METAL
    • B23H2300/00—Power source circuits or energization
    • B23H2300/20—Relaxation circuit power supplies for supplying the machining current, e.g. capacitor or inductance energy storage circuits

Definitions

  • the invention relates to a circuit arrangement for generating eroding pulses in a spark erosion system according to the preamble of patent claim 1.
  • the generic circuit arrangement is known from DE-OS 28 26 488.
  • an energy store for example in the form of a coil, is provided between the first switch and the primary winding.
  • the output of the energy store facing the primary winding is connected to the other terminal of the direct current source via a third switch.
  • a total of three freewheeling diodes are provided for the energy storage coil and the primary winding per circuit. All primary windings work on a common secondary winding.
  • Each circuit is designed so that a current pulse is only passed to the spark gap when the first and second switches are closed at the same time.
  • the generic circuit arrangement has the advantage of electrical isolation between the network and the spark gap. It also allows greater flexibility in the control of the system than the circuit arrangement known from DE-OS 29 08 696.
  • the circuit arrangement according to the invention manages without the energy store provided in the D E-OS 28 26 488, in addition to an associated freewheeling diode and a third switch. It is therefore much simpler. Nevertheless, pulses of any shape can be generated with it, as well as with the previously known circuit arrangement. Compared to the known circuit arrangement, it also has the advantage that the current-voltage behavior and the power losses in the energy store, the freewheeling diode and the third switch do not have to be taken into account in their control. Because of the wide range of control options, the residual ripple of the discharge current can also be freely set and the roughness of the workpiece surface to be machined can thus be varied. The circuit arrangement according to the invention is also distinguished by an increased generator efficiency.
  • the circuit arrangement according to claim 2 has the advantage that it permits particularly steep pulse edges, since the circuitry is based on the known "fly back" circuit principle.
  • the circuit arrangement according to claim 3 serves to further increase the control flexibility.
  • the partial currents can be kept unipolar in the simplest way.
  • the circuit arrangement according to claim 5 in turn enables the control flexibility to be increased with the simplest means.
  • the generator diagram shown in FIG. 1 shows a current source 1, from which a spark gap 3 is fed via two parallel loss-free circuits 2 A and 2 B, so that the current I through the spark gap 3 results from the sum of the partial currents I A and 1 supplied B results.
  • the basic principle of the circuit shown can be applied multiple times in the same way.
  • This control circuit itself is driven by a clock generator 5 via a clock signal S, so that it can be selected by the the machine, the input and
  • the elements of the circuit 2 A are identified by the index A, those of the circuit 2 B by the index B.
  • the circuits 2 A and 2 B are constructed identically. In the following description of the 2 A and 2 B circuits, the above-mentioned indexing can essentially be dispensed with.
  • Each circuit 2 has a first and a second controlled switch 21 and 22.
  • a current flows through the primary winding of a pulse transformer 23.
  • the current strength is recorded in a current measuring element 24 and adjusted in a first control stage 25 to a setpoint set there.
  • the actual value signal coming from the current measuring element 24 is compared with a predetermined target value stored in the control stage 25. As soon as the actual value signal has reached the setpoint signal, the control stage 25 switches the switch 21 to the non-conductive state.
  • the pulse transformer 23 is operated below its saturation. Current pulses on the primary side thus lead to current pulses or partial currents I A, B on the secondary side, the current strength of which corresponds to the transmission ratio.
  • the partial currents I A , B are kept unipolar by means of diodes 27.
  • the switches 21 and 22, which are preferably designed as transistors, are controlled from the control circuit 4 with the aid of the logic or control signals A , a or B, b assigned to the switches 21 and 22 via the first control stage 25 or a second control stage 26 it should also be noted that the switches 21, 22 lock in the circuits 2 when the control signal A, a, B, b is at logic "0", and switch through when the control signal is at logic "1".
  • the primary side of the pulse transmitter 23 is in series between the two switches 21 and 22. Furthermore, the diode 29 is parallel to the switching branch consisting of the first switch 21 and the primary side and the diode 28 is parallel to that of the primary side and the second Switch 22 existing switching branch switched.
  • the reliable ignition of the discharges via the spark gap 3 is brought about on account of the high induced voltages generated by the pulse transmission.
  • the circuit diagram also shows immediately that the spark gap 3 is completely galvanically decoupled from the generator circuit and can therefore also be operated in any polarity.
  • the total current I resulting from the superimposition of the two partial currents I A and I B is explained with appropriate control of the two circuits 2 A, 2 B by the control circuit 4.
  • the operator-operated clock generator 5 switches on the clock signal S, so that a pulsed partial current I A is supplied to the spark gap 3 via the transformer 23 A.
  • this is set to a time length (t 2 -t 0 ) that can be handled technically and thermally by the components used.
  • the time delay from t o to t s is known to result from the response delay typical of power circuits.
  • the second circuit 2 B is driven in advance, so that the partial current I B in it at the time t 1 begins to flow. Again, it is left switched on for a period (t 4 - t 1 ), taking into account its technical / thermal resilience.
  • the first circuit 2A switched on again in advance and so on.
  • the summation of the partial currents I A and I B results in the third drawn current I, which is generated alternately by the parallel circuits 2 A, 2 B as long as the clock signal S is on "duty cycle".
  • the shortest possible current duration is the period of time that can be achieved for the rising and falling edges of a current flow through a single circuit 2. This is stable with current commercially available components in the order of ⁇ s.
  • FIG. 3 shows the circuit diagram for the control circuit 4 for generating the control signals A, a, B, b which are assigned to one another via a circuit logic.
  • the clock generator 5 which is designed as an oscillator and supplies the processing circuit for the discharge pulses desired by the machine operator via the clock signal S
  • there is a further oscillator 41 within the control circuit 4 which generates a high-frequency pulse signal P of preferably rectangular pulses.
  • this pulse signal P after inverting to P, is fed by the inverter 48 to the clock input CK of a JK flip-flop 42. Its inputs J and K are set to logic "1".
  • the signals A "and B” are obtained, each via first AND gates 413 and 412 in signals A 'and B' and then each via second AND gates 415, 414 are converted into signals A and B.
  • the group of the first AND gates 412, 413 only allows the signals A ", B” to pass if a signal M supplied to them is at logic "1" at the same time.
  • the signal M is supplied by the output of a monostable module 47, to the control input of which the pulse signal P is supplied.
  • the monostable module 47 tilts from its stable to its unstable state on the positive edge of the pulse signal P.
  • the monostable module 47 thus achieves the inequality of the switch-off intervals with the switch-on intervals, which was already addressed in FIG. 2 in connection with the advance in time for the ignition of the subsequent pulse.
  • the falling edge of the signal M is used to control the timing of the ignition of subsequent pulses discussed.
  • the signals a and b are derived from the signals A and B.
  • the output signal A of the AND gate 415 or the output signal B of the AND gate 414 is fed to the one input of a first OR gate 417 or 416 as signal A "or B".
  • the signals a "and b" are therefore identical to the signals A and B.
  • a signal S is supplied to both OR gates 416, 417 as an alternative signal. This is the clock signal S inverted by an inverter 410.
  • the OR gates 416, 417 emit the signals a 'and b': These signals are at logic "1" as long as the clock signal S is at logic "0” . If, on the other hand, the clock signal S is logically "1", then the signals a 'and b' agree with the signals a "and b" and thus with the signals A and B.
  • the signals A and B can only be present alternately, the period between the falling edge of signal A and the rising edge of signal B - and vice versa - being equal to the duration, during which the signal M is at logic "0".
  • signals a and b it must also be ensured that they can only be at logic "0” if signal S is at logic "1"; furthermore, that a positive synchronization with the other signals, in particular the signals M and U, is brought about on the positive edge of the clock signal S.
  • the OR gate 416 is followed by a further OR gate 418, one input of which is supplied with the signal b '.
  • the alternative input of the OR gate 418 is acted upon by the Q signal of an upstream D flip-flop 46; the alternative input of the OR gate 419 from the Q output of a D flip-flop 45.
  • the OR gate 418 and 419 output the signals a and b.
  • Another D flip-flop 43 is located upstream of the two D flip-flops 45 and 46.
  • the clear input CL of the D flip-fop 43 is continuously kept at logic "1".
  • the flip-flops 43, 45 and 46 also satisfy the truth table shown in FIG. 3.
  • the clock input CK of the flip-flop 43 is supplied with the output signal U of the AND stage 411; the D input with the output signal B ′′ of the master flip-flop 42.
  • the signal R supplied by the Q output of the flip-flop 43 is fed to the D input of the flip-flop 45.
  • the signal R Signal R supplied to flops 43 is fed to the D input of flip-flop 46.
  • the clock inputs CK of flip-flops 45 and 46 are equally acted upon by the clock signal S, and the clear inputs CL by the output signal U of the inverter 49.
  • De mgezess is the clock signal of the clock S 5 to logic "0".
  • the output signals a 'and b' of the OR gates 416 and 417 and thus the output signals a and b of the OR gates 418 and 419 are permanently at logic "1". This already shows that
  • the signals M and U are derived from the pulse signal P, via the monostable multivibrator 47 (signal M) and the AND gate 411 (signal U).
  • the signal A is "mirror-symmetrical to the signal B".
  • the signal A ' coincides with the signal A and a ".
  • the signals a and a 'as well as b and b' agree with each other.
  • the control circuit 4 described with reference to FIGS. 3 and 4a to 4d can also be connected in parallel in a multiple version, as a result of which any pulse shapes with any amplitude can be generated. This is achieved by a suitable choice of the overlap of the pulses supplied by the individual control circuits and by a suitable choice of the interval between the pulses.
  • the clock generator 5 takes over the synchronous control of all control circuits 4 involved.
  • the parallel branches of the control circuits 4 can also be interconnected purely additively to increase the current in order to generate particularly strong current pulses.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Automation & Control Theory (AREA)
  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Electrochemistry (AREA)
  • Electrical Discharge Machining, Electrochemical Machining, And Combined Machining (AREA)
  • Inverter Devices (AREA)
  • Ignition Installations For Internal Combustion Engines (AREA)
EP85105692A 1984-05-11 1985-05-10 Arrangement de circuit pour la production d'impulsions érosives dans une installation d'étincelage érosif Expired EP0160995B1 (fr)

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
CH235384 1984-05-11
CH2353/84 1984-05-11
DE3422399A DE3422399C2 (de) 1984-05-11 1984-06-15 Schaltungsanordnung zur Erzeugung von Erodierimpulsen an einer Funkenerosionsanlage
DE3422399 1984-06-15

Publications (3)

Publication Number Publication Date
EP0160995A2 true EP0160995A2 (fr) 1985-11-13
EP0160995A3 EP0160995A3 (en) 1986-01-08
EP0160995B1 EP0160995B1 (fr) 1987-08-26

Family

ID=4231797

Family Applications (1)

Application Number Title Priority Date Filing Date
EP85105692A Expired EP0160995B1 (fr) 1984-05-11 1985-05-10 Arrangement de circuit pour la production d'impulsions érosives dans une installation d'étincelage érosif

Country Status (5)

Country Link
US (1) US4678885A (fr)
EP (1) EP0160995B1 (fr)
JP (2) JPS60242914A (fr)
KR (1) KR850008634A (fr)
DE (2) DE3422399C2 (fr)

Families Citing this family (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3639256A1 (de) * 1986-11-17 1988-05-26 Agie Ag Ind Elektronik Impulsgenerator zur funkenerosiven metallberarbeitung
JPS6411713A (en) * 1987-07-07 1989-01-17 Fanuc Ltd Electric discharge machining device
US5126525A (en) * 1988-11-01 1992-06-30 Sodick Co., Ltd. Power supply system for electric discharge machines
EP0401415B2 (fr) * 1989-06-09 1998-06-03 RABIAN, Laszlo Générateur pour la découpe par électro-érosion de pièces métalliques au moyen d'une électrode en matériau liquide ou solide
JPH0761568B2 (ja) * 1989-08-08 1995-07-05 三菱電機株式会社 放電加工装置の波形制御装置
JPH03104517A (ja) * 1989-09-18 1991-05-01 Mitsubishi Electric Corp 放電加工用電源装置
JP2890319B2 (ja) * 1989-12-06 1999-05-10 株式会社ソディック 放電加工機用電源回路
JP5143547B2 (ja) * 2007-12-28 2013-02-13 日本碍子株式会社 パルス電源回路
DE102012112480B4 (de) * 2012-07-04 2018-10-04 Dehn + Söhne Gmbh + Co. Kg Gekapselte, blitzstromtragfähige und folgestrombegrenzende Überspannungsschutzeinrichtung mit mindestens einer Funkenstrecke

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US3052817A (en) * 1958-03-19 1962-09-04 Republic Aviat Corp Method of and means for energizing spark-machining apparatus
FR1354354A (fr) * 1962-11-01 1964-03-06 Elox Corp Michigan Circuit d'alimentation pour usinage par étincelage
FR1446961A (fr) * 1964-09-18 1966-07-22 Aeg Elotherm Gmbh Montage électrique pour la production d'impulsions pour l'usinage de pièces métalliques par érosion par étincelage et procédé pour l'exploitation de ce montage
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JPS51137999A (en) * 1975-05-23 1976-11-29 Mitsubishi Electric Corp Intermittent discharge unit
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DE2826488A1 (de) * 1977-09-19 1979-03-22 Elmapa Nv Generator zum erzeugen von arbeitsimpulsen fuer die elektrisch abtragende metallbearbeitung mit mindestens einem hauptstromkreis
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DD149180A1 (de) * 1980-02-19 1981-07-01 Klaus Finner Generator zum erzeugen von impulsen fuer elektroerosive metallbearbeitung
DD150168A1 (de) * 1980-04-24 1981-08-19 Fritz Rothe Schaltungsanordnung zur erzeugung von impulsen fuer die elektroerosion
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JPS6029246A (ja) * 1983-07-13 1985-02-14 Fanuc Ltd 放電加工機における接触感知装置

Also Published As

Publication number Publication date
US4678885A (en) 1987-07-07
DE3560504D1 (en) 1987-10-01
KR850008634A (ko) 1985-12-21
DE3422399C2 (de) 1986-03-06
EP0160995A3 (en) 1986-01-08
DE3422399A1 (de) 1985-11-21
EP0160995B1 (fr) 1987-08-26
JPS60242914A (ja) 1985-12-02
JPH0585521U (ja) 1993-11-19

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